Bronchial hyperresponsiveness consists in excessive response to bronchial stimuli.Bronchial challenge test is used to confirm/exclude asthma (metacholine or histamine).Protection are used to avoid passive exposure of the technicians performing the test, despite the absence of evidence that they could develop a bronchoconstriction even if they suffer from BHR.The purpose of the study is to determine if patients with a high level of bronchial hyperreactivity and exposed passively to histamine during a bronchial challenge, are developing a bronchoconstriction, when placed in the same conditions that the technicians performing these tests.